Abstract: Objective:To investigate the clinical value of CT and digital mammography for diagnosis of breast neoplasm. Methods:Forty-five patients suspected as breast cancer underwent CT imaging and mammography,and compared to the results of histopathological examination. The differences in diagnosis were compared with these examinations. Results:The positive detection rates of CT and mammography were 84.4% (38/45) and 93.3% (42/45) respectively. The combination positive detection rate was 97.8% (44/45). In detecting breast cluster of calcification,the sensitivity of mammography was 73.3% (33/45),which was better than CT scan(46.7%, 21/45). The axillary lymph metastases were found in 34 patients. In detecting the axillary lymph metastases of the breast carcinoma,the sensitivity of CT scan was 88.2% (30/34),which was better than mammography(67.6%,23/34). Conclusions:The mammography and CT play the important role in diagnosis of breast neoplasm and showed the different character. The mammography combined with CT can improve the accurate rate of diagnosis.